全文获取类型
收费全文 | 2448篇 |
免费 | 124篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 66篇 |
儿科学 | 200篇 |
妇产科学 | 23篇 |
基础医学 | 207篇 |
口腔科学 | 43篇 |
临床医学 | 139篇 |
内科学 | 514篇 |
皮肤病学 | 65篇 |
神经病学 | 206篇 |
特种医学 | 47篇 |
外科学 | 443篇 |
综合类 | 154篇 |
一般理论 | 1篇 |
预防医学 | 80篇 |
眼科学 | 116篇 |
药学 | 106篇 |
中国医学 | 5篇 |
肿瘤学 | 162篇 |
出版年
2022年 | 21篇 |
2021年 | 61篇 |
2020年 | 28篇 |
2019年 | 46篇 |
2018年 | 49篇 |
2017年 | 33篇 |
2016年 | 40篇 |
2015年 | 74篇 |
2014年 | 92篇 |
2013年 | 135篇 |
2012年 | 144篇 |
2011年 | 162篇 |
2010年 | 99篇 |
2009年 | 71篇 |
2008年 | 117篇 |
2007年 | 138篇 |
2006年 | 138篇 |
2005年 | 81篇 |
2004年 | 83篇 |
2003年 | 79篇 |
2002年 | 91篇 |
2001年 | 47篇 |
2000年 | 51篇 |
1999年 | 50篇 |
1998年 | 31篇 |
1997年 | 19篇 |
1996年 | 13篇 |
1992年 | 43篇 |
1991年 | 39篇 |
1990年 | 52篇 |
1989年 | 43篇 |
1988年 | 33篇 |
1987年 | 28篇 |
1986年 | 19篇 |
1985年 | 19篇 |
1984年 | 22篇 |
1983年 | 17篇 |
1981年 | 10篇 |
1979年 | 23篇 |
1978年 | 13篇 |
1976年 | 15篇 |
1975年 | 12篇 |
1974年 | 19篇 |
1973年 | 18篇 |
1972年 | 16篇 |
1971年 | 11篇 |
1970年 | 12篇 |
1969年 | 19篇 |
1968年 | 23篇 |
1966年 | 12篇 |
排序方式: 共有2577条查询结果,搜索用时 31 毫秒
101.
Background and Purpose: The number of degree-awarding programmes in medical education is steadily increasing. Despite the popularity and extensive investment in these courses, there is little research into their impact. This study investigated the perceived impact of an internationally-renowned postgraduate programme in medical education on health professionals’ development as educators.Methods: An online survey of the 2008–12 graduates from the Centre for Medical Education, University of Dundee was carried out. Their self-reported shifts in various educational competencies and scholarship activities were analysed using non-parametric statistics. Qualitative data were also collected and analysed to add depth to the quantitative findings.Results: Of the 504 graduates who received the online questionnaire 224 responded. Participants reported that a qualification in medical education had significantly (p?<?0.001) improved their professional educational practices and engagement in scholarly activities. Masters graduates reported greater impact compared to Certificate graduates on all items, including ability to facilitate curriculum reforms, and in assessment and feedback practices. Masters graduates also reported more engagement in scholarship activities, with significantly greater contributions to journals. These qualifications equally benefited all participants regardless of age. International graduates reported greater impact of the qualification than their UK counterparts.Conclusion: A postgraduate medical education programme can significantly impact on the practices and behaviours of health professionals in education, improving self-efficacy and instilling an increased sense of belonging to the educational community. 相似文献
102.
Nils Korte Zeki Ilkan Claire L. Pearson Thomas Pfeiffer Prabhav Singhal Jason R. Rock Huma Sethi Dipender Gill David Attwell Paolo Tammaro 《The Journal of clinical investigation》2022,132(9)
Pericyte-mediated capillary constriction decreases cerebral blood flow in stroke after an occluded artery is unblocked. The determinants of pericyte tone are poorly understood. We show that a small rise in cytoplasmic Ca2+ concentration ([Ca2+]i) in pericytes activated chloride efflux through the Ca2+-gated anion channel TMEM16A, thus depolarizing the cell and opening voltage-gated calcium channels. This mechanism strongly amplified the pericyte [Ca2+]i rise and capillary constriction evoked by contractile agonists and ischemia. In a rodent stroke model, TMEM16A inhibition slowed the ischemia-evoked pericyte [Ca2+]i rise, capillary constriction, and pericyte death; reduced neutrophil stalling; and improved cerebrovascular reperfusion. Genetic analysis implicated altered TMEM16A expression in poor patient recovery from ischemic stroke. Thus, pericyte TMEM16A is a crucial regulator of cerebral capillary function and a potential therapeutic target for stroke and possibly other disorders of impaired microvascular flow, such as Alzheimer’s disease and vascular dementia. 相似文献
103.
Divjyot Kaur Piyush Ranjan Archana Kumari Anita Malhotra Gauri Shankar Kaloiya Ved Prakash Meena Prayas Sethi Naval K. Vikram 《Journal of obstetrics and gynaecology of India》2022,72(2):168
Background and AimsThe pregnancy weight is usually retained in the form of abdominal fat during the postpartum period. The willingness to lose weight is influenced by knowledge, attitude, beliefs and practices. This study aims to comprehend the awareness, beliefs and perspectives of postpartum women regarding their perceived factors, barriers and facilitators associated with post-pregnancy weight status.MethodsOverweight and obese postpartum women aged between 20 and 40 years and had delivered an infant in the last 2 years were recruited via convenience and purposive sampling techniques. The final sample comprised 27 participants with a mean age of 29.96 ± 4.50 years. Four focus group discussions and eight in-depth interviews carried out were audio-recorded and transcribed verbatim. Codes, sub-themes and themes were generated using Atlas.ti 9 software.ResultsMajor themes identified were perceived factors causing postpartum weight retention/weight gain including social and cultural beliefs related to diet and exercise specifically associated with this period, perceived motivators and deterrents of weight loss including eagerness to lose weight and perceived facilitators and barriers to weight loss including intrinsic and extrinsic factors such as time, energy, evidence-based knowledge about diet and physical activity, family support and obligation to family’s advice.ConclusionThe unique challenges and barriers associated with postpartum weight loss efforts should be taken into consideration by healthcare professionals and public health policy-makers to design strategies specific to postpartum women.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13224-022-01644-9. 相似文献
104.
To provide uniform heating of a tumour, it is necessary to establish sufficient volumetric control of power deposition. The interstitial Radio-Frequency Localized Current Field (RF-LCF) technique may provide such control when segmented electrodes are used. The length of segments is equal to 1-1.5cm. Each segment is connected to a separate power source. However, this technique requires an additional implant for interstitial radiotherapy, because the lumen of segmented electrodes is filled with wires necessary to connect each segment to a separate power source. In this work, a modified method of implant that allows delivery of sequential and concomitant controlled thermoradiotherapy was investigated. In this method, each segmented electrode is surrounded by four continuous electrodes. Continuous electrodes pass through vertices of 1.5x1.5cm square and a segmented electrode passes through the centre of the square. The distance between segmented and continuous electrodes is 1.06cm. The electric field induced between an electrically interacting segment and continuous electrodes is concentrated primarily between this segment and its projection on continuous electrodes. Therefore, control of temperature distribution achieved with a modified implant is similar to that achieved with an implant containing only segmented electrodes. For temperature control during treatment, plastic catheters are inserted at a 0.5cm distance from each segmented electrode. Temperature is monitored using multisensor temperature probes. The continuous electrodes are also used for placement of radioactive sources. The lateral distance between radioactive sources is equal to 1.5cm. Besides allowing a sequential and concomitant thermoradiotherapy, the modified method is simpler to implement because it uses several fold less amount of segmented electrodes and power sources. 相似文献
105.
Benefit of gluten‐free diet in idiopathic pulmonary hemosiderosis in association with celiac disease
Gulshan R. Sethi Kamal K. Singhal Amarender S. Puri Mukta Mantan 《Pediatric pulmonology》2011,46(3):302-305
Lane–Hamilton syndrome refers to the uncommon co‐occurrence of idiopathic pulmonary hemosiderosis and celiac disease (CD). Three children aged between 7 and 14 years with IPH were detected to have co‐existing non‐diarrheal CD. Institution of gluten‐free diet in each of the three children resulted in amelioration of the pulmonary symptoms along with improvement of anthropometric parameters and hemoglobin over a short‐term follow‐up period of 8–17 months. Inhaled/oral steroids and immunosuppressants could be weaned off after dietary exclusion therapy in each of the three children. Gluten free diet should be instituted in all patients diagnosed with Lane–Hamilton syndrome. It ameliorates both the pulmonary as well as the intestinal symptoms although the precise mechanism of the pulmonary response is as yet unclear. Pediatr Pulmonol. 2011; 46:302–305. © 2011 Wiley‐Liss, Inc. 相似文献
106.
Soha S. Abdelmoneim Jayant Talwalkar Saurabh Sethi Patrick Kamath Mohamed Mahmoud Fahmy Fathalla Benjamin R. Kipp Michael B. Campion Amy C. Clayton Kevin C. Halling Vijay H. Shah 《Liver international》2010,30(2):191-197
Background/Aims: Peripheral circulating endothelial cells (CEC) have been proposed as a prognostic marker in cardiovascular diseases. Cirrhosis and portal hypertension are associated with vascular injury yet little is known about CEC count in these conditions. Therefore, we evaluated CEC count in patients with cirrhosis, and correlated it with markers of portal hypertension/disease severity. Patients/Methods: Fifteen patients with cirrhosis/portal hypertension and 15 matched controls were prospectively recruited for study participation. An automated rare cell analysis system was used to enumerate CEC from peripheral blood and correlated with clinical features. Results: Median CEC levels were significantly higher in patients with cirrhosis as compared with controls (median [interquartile range (IQR)]; cirrhosis: 73.7 cells/4 ml [53.7–140.3]; controls: 28.7 cells/4 ml [21–58.7]; P=0.021). Ratio of CEC to platelet count (CEC/PC) also distinguished patients with cirrhosis from controls (IQR; cirrhosis: 0.723 [0.396–1.672]; controls: 0.126 [0.103–0.333]; P<0.001). Receiver operator characteristic analysis revealed that CEC cut‐off of 42 cells/4 ml showed sensitivity of 87% and specificity of 74% for differentiating cirrhosis from controls (AUC: 0.74), while CEC/PC ratio at 0.21 showed sensitivity of 100% and specificity of 73% (AUC: 0.89). Furthermore, CEC/PC index was significantly elevated in patients with hepatic decompensation as defined by Child B/C (P<0.05). The intra‐ and interobserver variability correlation coefficients for CEC measurement were 0.9989 and 0.9986 respectively. Conclusion: Median CEC count and CEC/PC ratio are significantly elevated in patients with cirrhosis, with CEC/PC also increased in patients with decompensated cirrhosis. These data provide rationale for larger validation studies to assess if CEC may have prognostic utility in patients with cirrhosis and portal hypertension. 相似文献
107.
Medical sciences are rapidly emerging as a data rich discipline where the amount of databases and their dimensionality increases
exponentially with time. Data integration algorithms often rely upon discovering embedded, useful, and novel relationships
between feature attributes that describe the data. Such algorithms require data integration prior to knowledge discovery,
which can lack the timeliness, scalability, robustness, and reliability of discovered knowledge. Knowledge integration algorithms
offer pattern discovery on segmented and distributed databases but require sophisticated methods for pattern merging and evaluating
integration quality. We propose a unique computational framework for discovering and integrating frequent sets of features
from distributed databases and then exploiting them for unsupervised learning from the integrated space. Assorted indices
of cluster quality are used to assess the accuracy of knowledge merging. The approach preserves significant cluster quality
under various cluster distributions and noise conditions. Exhaustive experimentation is performed to further evaluate the
scalability and robustness of the proposed methodology. 相似文献
108.
109.
110.
Micro-RNA (miRNA) mediated regulation of messenger RNA (mRNA) complexity in the central nervous system (CNS) is emerging as a critical factor in the control of CNS-specific gene expression during development, plasticity, aging and disease. In these studies, miRNA array and Northern blot based tracking of specific miRNA abundances and decay kinetics in human neural (HN) cells in primary culture and in short post-mortem interval (PMI, ∼1 h) human brain tissues showed a limited stability and relatively short half-life (∼1–3.5 h) for specific brain-enriched miRNAs. In short PMI Alzheimer's disease (AD)-affected temporal lobe neocortex, miRNA-9, miRNA-125b and miRNA-146a were found to be significantly up-regulated, an effect that was not seen in several related neurological disorders. The results suggest (a) that unless specifically stabilized, certain brain-enriched miRNAs represent a rapidly executed signaling system employing highly transient effectors of CNS gene expression, and (b) that in AD temporal lobe neocortex specific brain miRNAs are significantly up-regulated in abundance and strongly correlate with the presence of AD-type neuropatholgical change. 相似文献